Generally, a semiconductor device is tested to verify that it performs its intended functions before being shipped to a customer. For example, a memory is tested by writing various low and high data and reading back the data to verify the memory can store and provide the intended data. Testing OTP devices (e.g., OTP memory) is challenging because after an OTP cell of the memory is programmed, it cannot be reversed or reprogrammed. Stress testing OTP devices is also difficult. In a stress test, a device is generally subject to a combination of high temperature, high voltage and/or high current, which can cause the OTP device to be irreversibly programmed.
Requirement for testability and reliability for consumer products is normally less stringent than that for automotive-grade products. As a result, OTP devices for use in consumer products are generally tested to meet such general consumer product standards, which in many cases do not meet those of automotive-grade products.